This application relates generally to the field of radio wave antennas, specifically printed circuit board antennas with low-cost metal shields.
A radio frequency (RF) antenna incorporated into a printed circuit board (PCB) is well known in the art. Such PCB antennas are widely applied to wireless communication devices because they are relatively inexpensive to manufacture yet effective for low power communication. The use of printed circuit boards allows precise geometries of metal to be laid for RF-sensitive traces, such as radiating or receiving elements in a transmitter, receiver or transceiver.
Many household wireless devices use a nominal frequency of 2.4 gigahertz (GHz) (2.450 GHz center frequency). This frequency corresponds to one of the unlicensed industrial, scientific and medical radio bands standardized by the International Telecommunication Union (ITU). Such devices include cordless phones, Institute of Electrical & Electronics Engineers (IEEE) 802.11x wireless computer networks (Wi-Fi), X10 cameras, Bluetooth headsets, car alarms, microwave ovens, and other equipment. Because of the unlicensed nature of this band and its popularity among device manufacturers, common households and offices are often filled with stray 2.4 GHz signals.